You can tweak how your programs run in Windows XP by changing the priority at which they are run. This can dramatically increase the speed of the program in question

Open Task Manager (Ctrl+Alt+Del )
Go to the Processes tab
Right Click the Program- SetPriorityNow you can set the program to the priority of your choice.
Keep in mind you can speed up your system or slow it down so be careful.

If you have a Dual Core or Hyper-Threaded Processor like the P4 you can set the Affinityor how many cores each program uses

Open Task Manager (Ctrl+Alt+Del)Go to the Processes tabRight Click the Program- Set Affinity
Here you can choose which Processor gets used